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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"
  1. GRB 110301A: Fermi GBM detection
  2. GRB101225A: early EVLA Observations of Christmas Burst
  3. Swift/UVOT observations of GRB110223A
  4. No IPN GRB detected in conjunction with candidate GRB 110215
  5. GRB GRB 110223A: MASTER VWF early optical observations
  6. IBAS distribution of coordinates for low significance INTEGRAL GRB triggers
  7. Swift/UVOT observations of GRB110223b
  8. GRB 110223A: Swift-BAT refined analysis
  9. GRB 110223A : early optical limit by "Pi of the Sky"
  10. GRB 110223A: Liverpool Telescope observations
  11. GRB 110223A: Swift-XRT refined Analysis
  12. GRB 110223B: Swift-XRT refined Analysis
  13. GRB 110223A: Enhanced Swift-XRT position
  14. GRB 110223B: Enhanced Swift-XRT position
  15. GRB 110223B: Swift-BAT refined analysis
  16. GRB 110223B: GROND Detection of Optical Afterglow Candidate
  17. GRB 110223A: Observations from BOOTES-2
  18. GRB 110223B: Swift detection of a burst
  19. GRB 110223A: Swift detection of a burst
  20. GRB 101225A, the review of the sky area in plate archives
  21. OT 110215: Further NIR observations from NOT of the GRB candidate
  22. GRB 110213B: Swift/UVOT observations
  23. GRB110213B: X-ray afterglow confirmation
  24. Fermi GBM detection of an SGR-like burst
  25. Swift XRT and UVOT Observations of OT 110215
  26. OT 110215: NIR observations from NOT of GRB candidate
  27. GRB 110213A: optical observations in CrAO
  28. GRB 110213B: GROND observations of the optical/NIR afterglow
  29. GRB 110213A: optical observations in Mondy
  30. Fermi GBM trigger 319534757 (110216319) is not a GRB
  31. GRB110205A: EVLA Observations
  32. OT 110215: possible GRB from 2MASS J00264184+8324093
  33. Swift/UVOT observations of GRB110210a.
  34. GRB 110210A: optical upper limit
  35. GRB 110213B: Gemini South Redshift
  36. GRB 110213B: Possible Host Galaxy in SDSS Stripe 82 Imaging
  37. GRB 110210A: ROVOR Upper Limit
  38. GRB 110213A: YNAO-GMG Observations
  39. GRB 110213B: P60 Optical Afterglow Candidate
  40. GRB 110213A: TNT optical observations
  41. GRB110213A: RAPTOR Early Optical Peak and Plateau Measurements
  42. GRB 110212A: Swift XRT and UVOT observations
  43. Swift GRB110213A: interesting behaviour
  44. GRB 110213A: Fermi GBM observation
  45. GRB 110205A: Konkoly optical observations
  46. GRB 110213B: Swift XRT observation
  47. GRB 110213A: MITSuME Akeno Optical Observation
  48. Konus-Wind observation of GRB 110213A
  49. Konus-Wind observation of GRB 110213B
  50. GRB 110213A: Swift-XRT refined Analysis
  51. GRB 110213B: MAXI/GSC refined analysis
  52. GRB110213A: MITSuME Okayama Optical Observation
  53. GRB 110213A: Swift/UVOT refined analysis
  54. GRB 110213A: THO optical observations
  55. GRB 110213B: MAXI/GSC detection of a probable GRB
  56. GRB 110213A: Lightbuckets Optical Observations
  57. GRB 110213A, Swift-BAT refined analysis
  58. GRB 110213A: optical observations
  59. GRB 110213A: Enhanced Swift-XRT position
  60. GRB110212A: MITSuME Okayama optical upper limits
  61. GRB 110213A: KAIT observations
  62. GRB 110213A: GRAS011 optical observations
  63. GRB 110213A: Bok Telescope Redshift
  64. GRB 110213A: ROTSE-III Detection of Optical Counterpart
  65. GRB 110213A: P60 Optical Afterglow Detection
  66. GRB 110213A: Swift detection of a burst with optical afterglow
  67. GRB 110212A: GRT Optical Observation
  68. GRB 110212A, Swift-BAT refined analysis
  69. GRB 110212A: SARA-N Optical Limits
  70. GRB110212A: BOOTES-2/TELMA optical limits
  71. GRB 110212A: ROTSE-III Optical Limits
  72. GRB 110212A: Swift detection of a burst
  73. GRB 110201A: Subaru/MOIRCS Ks-band photometry
  74. Konus-Wind observation of GRB 110205A (correction to GCN 11659)
  75. GRB 110205A: detection of optical linear polarization from CAHA
  76. GRB 110207A: Suzaku WAM observation of the prompt emission
  77. GRB 110210A: optical upper limit
  78. GRB 110210A: Swift-XRT refined Analysis
  79. GRB 110205A: Swift/BAT and Suzaku/WAM joint spectral analysis
  80. GRB 110210A: Swift-BAT refined analysis
  81. Swift-BAT refined analysis of outburst from 1E 1841-04.5
  82. GRB 110210A: Enhanced Swift-XRT position
  83. GRB 110201A: optical observations
  84. GRB 110210A: Swift detection of a burst
  85. GRB 110206A: Swift-XRT confirmation of the X-ray afterglow
  86. GRB 110208A: Magellan confirmation of the optical afterglow
  87. Fermi GBM detection of a burst from 1E 1841-045
  88. Swift/UVOT observations of GRB110208a
  89. GRB 110205A: Suzaku WAM observation of the prompt emission
  90. GRB 110208A: Potential afterglow from Magellan
  91. GRB 110207A: Swift-XRT observations
  92. GRB 110208A: Swift-XRT refined Analysis
  93. GRB 110208A: Enhanced Swift-XRT position
  94. GRB 110208A: Swift-BAT refined analysis
  95. GRB 110208A: Magellan optical observations
  96. GRB 110206A: SMARTS optical/IR afterglow decay
  97. GRB 110208A: Swift detection of a burst
  98. SGR-like outburst from the magnetar 1E 1841-04.5
  99. GRB 110205A: optical observations in Mondy observatory
  100. GRB 110207A: Fermi GBM observation

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